Steam-expansion engine



V. B. HARLEY-MASON.

' Patented June 15,1920. v

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STEAM EXPANSION ENG APPLICATION FILE D FEB=2| 1,343,449. Paten une 1 20.

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v l STEAM-EXPANSIQN:ENGINE.

To all whom it may concern:

Be it known thatII, VERNON BALFoUr. HAR nY-MAsoN, a subject of the Kingof Great Britain, and aresident of Cheain,

Surrey, England, have invented certain new and useful Improvements inSteam or like Expansion Engines, of which the followlng is aspecification.

This invention relates to steam or like expansion engines, and hasreference particularlyto steam engines where steam or other elasticfluid is expandedbetween a hollow piston and a cylinder cover conformingto the internal contour ofjthepiston. The'invention is particularlyadvantageous in an in the specifications 01". Nos; 1,145,391 and 1230617granted to 'William Joseph'Still, which 'al though an internalcombustion engine also operates under steam expanded at th'ebacks of thecombustionfenginepistons.

. In such engines as hi herto constructed it is. necessary to provide,clearance between the pistonland the cylinder cover for the passage ofthe steam, and although these clearance spaces "are small in themselves,the total clearance volume is quite considerable and in many cases,amounts to as much as 16% or 20% of the/ total steam space. a

The object of the present invention is to eliminate the clearance spaceto a large extent and provide for rapid and effective admission andexhaust of the steam. 'A

method of effecting the exhaust of the products of combustion from thecylinder of an internal combustion engine which has been suggested is toprovide the edge of the skirt of a hollow piston with teeth so as toform slots which act as exhaust ports and become uncovered when thepiston reaches the end of its firing stroke. .In no cases, however, hasthe object of reducing clearance been in view, and moreover thearrangements proposed could not be applied to an engine whereincombustion takes place on one side of the piston and steam expansion onthe other. The present invention consists of a particular constructionand arrangement of piston and cylinder which results. in much reducedsteam clearance spaces and renders possible the application of theforegoing method of exhaust to the steam side of engines whereincombustion takes place on one side of the piston and steam expan-Specification of Letters Patent. Patented J 11116 15, 1920. Applicationfiled February 21,1920. SerialNo. 3 0,4 2, g

sion on the other. I Thisparticular construction comprises essentially ahollow piston having a piston'rod'f'connected to the 1n-- edge of thepiston skirt, saidslots consti tuting exhaust ports which uncover when?the piston approaches the end of its expansion stroke and permit thesteam topass to an exhaust pipe or pipes communicating with the annularpassage in which the pieton skirt slides in steam tightengagement bothwith" the cylinder wall and cylinder cover. i p

The invention" further comprises the provision of improved means i foradmitting steam to the interior of the piston, which.

consists in providing a passage or passages in the piston rod leading tothe interior. of

the piston and cooperating with an. inlet in thecylinder cover, suitablyv port or ports disposed me'tallic'packings being provided.

through which 'the p iston rod slides; s

In the accompanying drawings I have illustrated my nventiondiagrammatically,

Figure 1 being a sectional. view of a'piston and cylinder coverin'itsrelation with the cylinder, and Fig. 2 is a similar view of a tratingthe arrangement for introducing steam to the interiorof the pistonthrough the piston rod. I Referring to these drawings and particularlyto Fig. 1, it will be seen that I provide piston rings 1 between thewall of the cyla inder cover 2 and the piston 3, so that the pistonskirt 8 and the cylinder cover maintains steam tight engagement one withthe portion of a piston and cylinder cover illusother, and I form theedge of the piston with teeth 5 so that when the expansion strokefinishes, the ports formed between the teeth open to permit exhaust, thearrangement being such that the packing rings never become disengaged.In the drawings the packing rings 1 are shown as fitted to the cylindercover, which is the preferred arrangement, but it will be appreciatedthat in some cases this arrangement may be reversed and the packingrings be carried: by the pistonskirt. The preferred arrangement will beclear upon reference to Fig.1. The teeth 5 of the piston may be formedwith channels 6 cut behind the pistonrings 7 so as to economize inoverall height of the engine.

In Fig. 2 of the drawingsI have shown an arrangement wherein the steamis admitted from aninlet port 8 .in the cylinder" cover" through a portor-passage 8 in the piston rod 9; this port being controlled asaforesaid by sliding cooperation with the inlet become chargedwith oilto an extent since i the time during which the lubricated surfaces arein contactwith the steam W111 be much'reduced. Moreover a certainamountof exhaust valve operatlng gear can be entirely dispensed 'With Vj WhatoI claim and desire to secure by-Letmternalshapeofthe piston, an"exhaust.

ters Patent is 1., In a steam expansion engine; a cylin der, a "hollow pston therein and having a skirt provided with exhaust ports, an in-Wardly projecting cylinder cover" conforming to,,the;internal shape ofthe piston, an ex-' haust pipe communicating with the annular spaceformed betweenthe cylinder and the inwardly projecting portion of thecover, and a piston rod connected to the crown of the piston and slidingthrough said cover,- the said exhaust ports of the piston skirt beinguncovered when the piston approaches theend' ofits expansion stroke andpermit 7 f ting steam lto pass-through said annular space'and' to jsaidexhaust plpei In a steam expansion engine, a ,cylinder, a hollow pistontherein having a skirt provided with'exhaust ports, an inwar'dlyprojecting cylinder cover conform ing to theinternalshape ofthe piston,an exhaust pipe communicating with the annular space formed between thecylinder and the interior of the piston and said cylinder cover havingan inlet portto coact with the piston rod port to admit and cut oii thesupply of steam tothe cylinder. 7 r

3. In a steam expansion engine, acylinder, a hollow piston therein andhaving a skirt provided with exhaust ports, aninWardly projectingcylinder cover conforming tothe pipe communicating with theannular spaceformed between the cylinder and the 'inwardly projecting portlon of thecover, and 7 apiston rod connected tothe crown of the piston and slidingthrough said cover, the said exhaust ports ofthe piston skirt beinguncovered when theplston approaches the end of itsexpansion stroke andpermitting] steam. to pass throughsaid annular space and to said exhaustpipe; the skirt of the piston having piston rings near its outer end andalso having channels out behind said rings and forming extensions of theinner ends of said exhaust ports.

r In witness whereof afiix my signature;

7 VERNON BALFOUR HARIiEY-lll ASOll.

